import java.util.Scanner;

public class dome3 {
    public static void main(String[] args) {
        System.out.println("请输入本次购物价格");
        Scanner sc=new Scanner(System.in);
        double price= sc.nextDouble();
        System.out.println("包邮吗？");
        Scanner sc1=new Scanner(System.in);
        String select=sc1.next();
        switch (select){
            case "yes":
                System.out.println("您需付款"+price+"元");
                break;
            case"no":
                price+=20;
                System.out.println("您需付款"+price+"元");
        }
    }
}